Hydraulic pump



@w R. F. HQRTQN 294579191 awmwuc PUMP Filed Feb, 28, 1945 3 Shuts-Sheet];

fan now BY 14 426 Q ATTORNEY mm L 194.

HYDRAULIG PUMP 3 shee'is -sheet 2 Filad Feb. 28, 1945 M ATTORNEY R. F. HRTQN HYDRAULIC PUMP Dec. 21 1W4,

5 sheets sheet 3 Filed Feb. 28, 1945 INVENTOR aff/: /%Pm/v,

4 7 ATTORNEY Patented Dec. 21, 1948 UNITED STATES PATE'NT- orrics HYDRAULIC PUMP Roger F. Horton, Hempstead, N. Y.

Application February 28, 1945, Serial No. 580,142-

8 Claims. .1 I

This invention relates to an hydraulic pump.

An object of the invention is to provide a simple, economical and efficient hydraulic pump adapted for operation at high pressures.

Another object of the invention is to provide an hydraulic pump having less internal friction and therefore less power loss within the pump than has heretofore been attainable.

Another object of the invention is to provide a high speed hydraulic pump having a greater horsepower output per pound, of weight than has heretofore been available.

Another object of the invention is to provide means for increasing the centrifugal energy of low pressure fluid revolving within the pump casing and to eliminate the need for separate booster pump means to fully fill the cylinders of the cylinder block at high speed.

Another object of the invention is to utilize heretofore unused means without further complieating the mechanism for supplying the fluid to the rotor cylinders with increased energy.

Another object of the invention is to provide an hydraulic pump readily adapted for opposite hand rotation of the rotor.

Another object is to provide an hydraulic pump in which internal friction is greatly reduced by the substitution of rolling friction for sliding friction, thereby permitting higher speeds and higher loading per square inch of bearing surface.

Another object of the invention is to provide an hydraulic pump which is capable of higher speeds than have heretofore been attainable by prior art pumps without the aid of separate booster pump means.

Another object of the invention is to provide means for pumping more fluid at higher pressure with less weight and size, at higher over-all efilciency.

Other objects of the invention will be in part obvious or in part pointed out hereinafter.

This inveniton accordingly consists in the features of construction, combinations of elements, arrangements of parts, and in the several steps and relation and order of each of said steps to one or more of the others thereof, all as will be pointed out in the following description, and the scope of the application of which will be indicated in the following claims.

The invention will best be understood if the following description is read in connection with the drawings, in which,

Figure Us a front elevation of an embodiment of the invention, taken on the line i'-i of Figure 2, partly cut away and partly in vertical section;

Figure 2 is a side elevation taken on median line of Figure l in a plane passing through the axis of the pump, partly cut away and partly in section;

Figure 3 is a longitudinal sectional view of the pintle indicated in Figures 1 and 2, showing its conecting fluid ports and conduits;

Figure l is a vertical transverse section taken on. line lt of Figure 3;

Figure 5 is a front elevation, partly broken away and partly in section, showing the path of the fluid;

Figure 6 is a side view, partly in longitudinal section and partlyin dotted lines, showing the relation of thepump parts and the path of the Figure 7 is a detail view in vertical section showing the unbalanced nature of the frictional con-= tact between the respective pistons oi the radial cylinder block and a grooved surface oi the track ring;

Figure 8 is a plan view of the detail shown in Figure 7;

Figure 9 is a detail view of one of the track ring upporting members shown in Figure 2;

Figure 10 is a side view of a section of the member shown in Figure 7.

, In the following description the term drive end is used with respect to elements of the pump to indicate the end which is nearer or extending toward the mechanical input side of the pump, and the term anti-drive end is used to indicate the end extending toward, or which is nearer, the hydraulic high pressure output side of the motor.

My hydraulic pump comprises a closure which may have a combined casing iii and mounting flange ii, and a casing cover 82, the cover I! being joined to the casing i0 as by machine screws 62. The casing cover i2 is provided with a central bore into which extends the pintle i3 having the flange iil overlying the outer face of casing cover it and being secured thereto by the studs H and nuts l5 respectively. Pintle l3 has at its drive end a wearing plug l6 which abuts against wearing plug i'i fixed in the anti-drive end of the hollow drive shaft i8 which carries at its other extremity the pump driving spline 52.

The pintle it is provided with two longitudinally extending bores i9 and 20 respectively, which are closed at the drive end but open at the anti-drive end. The bores. i9 and 20 respectively, adjacent the drive end of pintle iii, are internally threaded to receive the externally threaded plugs 2| and 22 respectively. Bore I9 is provided with a port 23/e'xtending radially and bore 20 is provided with a port 24 extending 3 through the pintle shell,

radially through the pintle shell, and spaced substantially 180 around the pintle surface from port 23. Bore I9 is also provided with port means, spaced toward the anti-drive end of the pintle from port 23 and adapted to register with conduit 28 which extends through the wall of casing cover l2, from mouth 53 at the inner periphery of the casing to its outlet which is in register with the pintle surface. As shown this port means comprises the two peripherally spaced ports 25' and 25 separated by the web 25 The ports 28 and 25 serve to communicate with borel8 at all times the particular one of these bores which will intercommunicate between the outlet end of conduit 28 and bore i8 depending upon the direction of rotation of the cylinder block for which the pintle is set, one setting being 180 removed from the other setting as will be explained.

Revolvably mounted on pintle i3 is a rotor assembly 21 (Figure 2) comprising the radial cylinder block 28 having cylinders 28, preferably seven in number, in the bores of which pistons, 28, are freely mounted, so that they are slideable and also rotatable about their respective longitudinal axes. said pistons being provided'with generally-spherical heads 80, having a small relief or flat area H. at the top of the dome, adapted to prevent contact between the extreme top center of the piston head, and a groove 32, provided in the inner surface of track ring 33, and into which said pistons 28 extend. Preferably the radius of the spherical head of the pistons and the radius of the groove 32 is substantially the same. That is they ideally have the same radius allowing for the tolerance inherent in the machining of their parts. The resulting contact between pistons 23 and track 33 is a rolling contact,'due to the extremities of the heads being relieved, and because, as I found in a practical embodiment of the invention, the friction forces due to contact on diametrically opposed sides of any of said pistons are unbalanced due to variations in tolerance, which. at the present time with present manufacturing tools, are inevitable and unavoidable. Accordingly there will be in practice a frictional force F on one side of the piston center; greater than the theoretically balanced forces I (Figure 8), causing pistons 28 to rotate within their respective cylinders about their own axes respectively as well as rotating aboutthe pintle with the cylinder block during their reciprocal action, as shown in Figures 1 and 2, and thus have predominantly a rolling contact with the track ring which also rotates about the pintle at speeds approximately those of the rotor. Track ring 33 is supported by radially extending supporting members 34 and 35, arranged in opposed, laterally spaced relation, and by. the bearings 38 and 31 respectively, positioned concentrically around the outwardly extending flange portions of the members 34 and 35 respectively, which are seated respectively in bores eccentric to the pintle and cylinder block and provided in opposed relation inthe inner faces of casing l0, and casing cover l2, respectively.

'The radially extending support members 34 and 35 are provided with'outwardly opening radial slots 5] to be described;

At the drive end of radial cylinder block 28 the circular flange 38 is bored to provide a circle of spaced holes extending parallel with the cylinder block axis, and the internal face of flange 33 is then ground out-to convert the holes, throughout a portion of their depth, into the half holes or the cylinder block so that the half holes of flange 39 may complement the half holes of flange 38 to form complete cylindrical spaces, and in these spaces cylindrical pins 40 are inserted. There is thus provided alarge diameter high torque spline between cylinder block 28 and drive shaft l8 by which the drive force is transmitted tothe latter from the former, and with a minimum offriction in the event of axial misalignment for any reason.

Extending around drive shaft l8 and serving to retain it in position of engagement with driving pins 40 of thecylinder block 28 is a coil spring 4i, which is retained between the drive shaft flange ,33 and a collar 42 extending around the driving shaft and turning with it. Suitable packing 43 may be provided between collar 42 and shaft l3, and also suitable packing may be provided between the collar 42 and end plate 44 secured to mounting flange II as by screws 44. Preferably packing 43 is of an oil resisting material such as neoprene. The packing between collar 42 and end plate 44 may desirably comprise a ring 45 of morganite or bronze having a lapped surface pressed against the lapped-surface of a ring 46 of cast iron by action of collar 42. Preferably also an oil seal 41 is provided between the mounting flange H and the end plate 44.

As shown in Figure 3 fluid is supplied to the pump l0 through conduit 48, which communicates with the open end of a conduit 48 extending through the wall of pintle flange I3, and which in turn communicates with a port 50 extending through the wall of casing cover i2 and adapted to lead fluid into the interior of the casing into the space therein surrounding cylinder block 28. The track ring support members 34 and 35 are provided with outwardly opening radially extending slots 5| (Figure '7), the open ends of which point toward the periphery of the casing. Fluid is supplied into the pump casing through conduit of course driven by power which 'is applied at spline 52, and which is transmitted to the cylinder block through the drive shaft l8 and the cylindrical pins 40; interconnecting the drive shaft and the cylinder block. As the cylinder block and track ring assembly rotate fluid, entering into the pump casing through port 50, from conduit 43 through the pintle flange I3 and supply conduit 43 successively, fills the radial slots 5i and is discharged from said slots by centrifugal force engendered by the rotation of the cylinder block and track ring assembly. The fluid thus forcibly discharged from slots 6| adds to the centrifugal force of the fluid in the casing which is thus supplied at increased speed into the mouth 53 of conduit 28 which leads back to port 25 of the pintle. Fluid entering into the interior of the pintle through port 25 passes axially through bore l8 and is discharged therefrom through port 23 which communicates through the interior of radial cylinder block 28 with the inner ends of the bores of the cylinders 2fl 'respectively, the pistons 29 .for said cylinders respectively being, at the time of communication with said port 23, at substantially the end of their outward travel, due'to the eccentricity of the axis of the track assembly with respect to the pintle axis. The incoming fluid will thus flow into the cylinders successively at low pressure and will in turn be forced out of the cylinders at high pressure by the return stroke of the piston members respectively, and discharged through pintle port 24 into the pintle bore 20 through which the fluid, now at high pressure, is delivered to perform the desiredwork.

The direction of rotation of the cylinder block of the pump disclosed herein may readily be reversed. For this purpose a port 50", similar to port 50, is provided through the wall of the easing but substantially 180 removed from port 50. For opposite hand rotation it is only necessary to remove nuts i and studs I4, which secure pintle flange l3 to casing cover I2, and rotate the pintle 180 with respect to the pump casing and its cylinder block and track assembly, thus changing by 180 the angular position of the cylinders when they are charged, and thus reversing the direction of rotation of the cylinder block. The pintle flange may then again be secured to the casing cover and the opposite hand rotation of the pump may be continued as long as desired, the operation being the same as that described above except that fluid supplied to conduit 49 through conduits 48 will enter the casing through port 50 instead of through port 50.

Radial slots 5| are provided in support members 34 and 35, asstated above, to add centrifugal energy to the fluid supplied to the cylinders from the casing for the purpose of completely filling the displaced volume in the cylinders during each piston stroke, and thereby make up for the loss of energy occurring between-the reservoir and the pump cylinders and to increase the maximum velocity and speed at which the fluid may be supplied from a fluid reservoir to the casing and from the casing to the cylinders of the cylinder block. In this way a volume of fluid sufficient to completely fill the cylinders at all speeds, may be supplied to the cylinders at increased pressure for conversion from low pressure to high pressure,

thereby making it unnecessary to use accessory supercharging pumps which are commonly used with piston type pumps.

Since the slots 5| are an integral part of the design of my pump they can be modified as to size and number so that the fluid delivery characteristic of the pump can be made to exactly fit the requirements of the pump at all speeds. A supercharging pump is not only an accessory and an additional piece of equipment and therefore undesirable but it has its own limitations and they limit the-main pump, but this is not the case with my integrally formed supercharging means provided by slots 5| It will be noted that by the provision of slots II I have not only added increased energy to the fluid supplied to the pump cylinders but in so doing I have utilized energy which has heretofore been wasted. Y

Since the fluid 'within the casing, and particularly the portion which is radially beyond the track ring 33, is rotating with the track ring and the ring supporting members 34 and 35, prior to discharge, the force with which the fluid is supplied to mouth-53 of conduit 26 can be calculated from the formula F==Mr where M=mass oi fluid under consideration; 1': the distance from the mass center of the fluid to the center of rotation; and w=the angular velocity of this mass center about the center of rotation.

In order to increase the volume of fo rce F I increase all elements in the above equation by proper arrangement of radial slots 5|, the eccentric center of track ring 33, and the mouth 53 of conduit 26. It will be seen by reference to 10 Figures 1 and 6 that this is accomplished as and the discharge passage 54 v follows: The center of the mouth 53 of conduit 26 and the eccentric center, a, of the track ring, are located on diametrically opposite sides of the center, b, of the pintle. This arrangement provides in effect two semi-circular complementary chambers c and c', which together completely encircle the track ring 33, and which are identical in size and shape, each having a constantly increasing mean radius. Only one of these cham hers is active in adding centrifugal force to the fluid within the casing for each direction of rotation of the rotor assembly. The co'nstantlyincreasing mean radius of the chamber which is active, and into which fluid is continuously being forced by the radial slots 5|, provides a constantly increasing M, or mass, as the fluid approaches the mouth'53.of conduit 26, and also provides a constantly increasing 1. Since w is a function of r, w is also constantly increasing.

- work.

Thus three factors in the equation are constantly increasing, from a minimum at a point diametrically opposite the said mouth 53 to a maximum at the mouth itself. In addition to this arrangement the size and number of the radial slots 5| can be determined so that fluid is thrown out of them into the chamber which is active in building up centrifugal force in a volume proportional to the chambers increase in volume, and

consequently the supercharging pressure increases in proportion to' the pump speed. Thus, there is provided a simple and effective centrifugal pump specially designed to increase the flow of fluidto the working cylinders of a given pump, making it possible for them to perform more net The hydraulic pump described herein has the great advantage that it may be embodied in a unit of small size. The pump due to the elimination of sliding members and'resultant decrease of friction is characterized by increased efficiency per pound of pump weight as compared with prior art hydraulic pumps.

It will thus be seen that there has been provided by this invention an apparatus in which the various objects hereinabove set forth together with many thoroughly practical advantages are successfully achieved. As various possible embodiments might be made of the mechanical features of the above invention and as the art herein described might be varied in various parts, all without departing from the scope of the invention, it is to be understood that all matter hereinbefore set forth or shown in the accompanying drawings is to be interpreted asillustrative and not in a limiting sense.

What I claim is: 1. In a radial pump, a casing, a" pintle centrally in the casing, and a rotor assembly rotatable in said casing around said pintle including a radial cylinder block, a track ring, means for supporting the track ring comprising members positioned on opposite sides of the rotor each having,

an annular, radially extending disk-like portion and a hub portion, said casing having bearings to receive said hubs respectively, said i disk-like mounted portions having their outer peripheries in interengagement with the sides of the track ring respectively, said pintle having two axially extending bores and two circumferentially spaced ports communicating between said bores respectively and the interior of said cylinder block, and having a third port communicating with one of said bores, and spaced axially of the pintle from said other ports, a. conduit extending through the casing wall and communicating between the interior of the casing and said third port, means for delivering low pressure fluid into said casing, means for acting on the fluid within the casing to increase its rate of flow from within the casing to the interior of thecylinder block, said means comprising cut outsin said disk-like portions extending radially of said portions and open at the outer periphery of said portions forming slots adapted to be filled with fluid within the casing and to discharge itunder centrifugal force, and

conduit means adapted to register with one of the said pintle bores to receive high pressure fluid from the pump.

r 2. An hydraulic pump comprising a casing providinga circular closure, apintle mounted centrally in the casing, a radial cylinder block, mounted for rotation around said pintle and concentric therewith, means for supplying fluid into said casing between, the pintle and said track ring,

a track ring, and support means therefor mounted in said casing for rotation about an axis eccentric to the axis 01' said pintle, and pistons in the cylinders of said block adapted tocontact said track ring and to cause it to rotate when said means for said track ring including radially dismediate the rotor and the casing, rotatably posed slots opening outwardly into the said space between the track ring and thecasing wall, and

adapted, when the cylinder' block is rotating, to discharge fluid into said space, and means interconnecting said discharge port and the cylinders of said cylinder block.

3. A radial pump comprising a casing, a pintle having two fluid passages extending into said casing, a radial cylinder block mounted for rotation on said pintle, means for driving said cylin- V der block for rotation about the pintle, track means located within said casing eccentrically with respect to the axes of said pintle and said cylinder block, and support means for said track ring extending from between the cylinder block and the casing to the track ring and having radially extending slots opening outwardly beyond the track ring and adapted to receive fluid and to discharge it by centrifugal force toward the periphery of the casing, means for supplying fluid into the casing, and conduit means including one of said pintle passages for receiving the fluid discharged from said slots and supplying it to the interior of said cylinder block. the other of said pintle passages-serving to receive and transfer fluid which has been acted on by the pistons of said cylinder block.

4. An hydraulic pump comprising a casing providing a circular closure, a pintle mounted centrally in the casing. a radial cylinder block, mounted for rotation around said pintle and concentric I therewith, a track ring, and support means therefor mounted in said casing for rotation about an axis eccentric to the axis of said pintle, and pistons in the cylinders of said block adapted to contact said track ring and to cause it to rotate when said cylinder block is rotating, the space within said casing between said track ring andthe casing wall comprising in eflect two similar chem: bers each having at all times its greatest cross sectional area diametrically opposite said pintle axis from said eccentric axis, and a fluid discharge port located in the casing wall at a point diametrically opposite the pintle axis from said eccentric axis and therefore ina position to receive fluid from said chambers respectively in the locality of their greatest cross sectional area.

5. In a radial pump. a casing, a pintle mounted centrally in the casing, a rotor assembly rotatable within the casing around said pintle, means for supplying propulsion fluid into said casing between the rotor and a track ring, a track ring intermounted support means for the track ring including outwardly opening radial slots each adapted to collect fluid introduced into the casing and discharge it under centrifugal force toward the peripheral .wall of the casing and beyond the track ring, a port in'the casing wall located beyond the track ringand on the far side of the rotor axis from the axis of the track ring, and a conduit interconnecting said port and the cylinders of said rotor assembly. I V

6. A radial pump comprising a casing, a pintle mounted centrally in the casing, a cylinder block mounted for rotation on the pintle and including a number of radial cylinders and pistons in said cylinders respectively, and a track ring assembly positioned between the cylinder block and the casing, eccentrically with respect to the axis of said pintle and said cylinder block, and including a circular track aligned with the cylinders of the cylinderblockand adapted to be contacted by the pistons of said cylinders, and means for suptween the cylinder block and the track ring and A the space between the track ring and the casing, and adapted when the track ring is rotating to discharge oil present within its casing toward the periphery of the casing under centrifugal force, means forintroducing oil into the casing through anropening in the casing located substantially in alignment with the inner ends of the said slots, and a discharge passage extending.

through the casing wall and having its inlet at the periphery of said casing'a'nd substantially in alignment with the outer ends of saidslots, and

having its outlet in communication with thecylinders of the cylinder block.

7. In a pump comprising a casing, a pintle positioned within the casing, a radial cylinder block mounted for rotation around saidpintle and concentric therewith, and a track ring rotatable about an axis eccentric to the axis of said pintle,

' a track assembly characterized by track ring support means including hub means rotatably mounted in the casing and radially extending means interconnecting the hub means and the track ring, said radially extending means having outwardly opening slots adapted to tlll with propulsion fluid present within the casing and discharge it under centrifugal force when said track assembly is rotated.

8. In an hydraulic pump comprising, a casing, a pintle, a cylinder block mounted forrotation on the pintle, and a track ring assembly mounted eccentrically with respect to the axis of the sylinder block intermediate the cylinder block and the casing wall, in which the space between the cylinder block and the casing wall is illled with oil or other propulsion fluid employed, an inlet passage extending through the side wail of the casing to introduce low pressure fluid directly into the casing, an outlet passage leading from the 1 eriphery of the casingthrough the casing wall and adapted to communicate with a conduit in the pintle leading to the cylinders 01' the rotor. and means within the casing for supercharging the fluid delivered from within the casing through said outlet passage and said pintle to the cylinders oi the rotor comprising slotted members forming part oi. said track ring assembly disposed on opposite sides of said rotor cylinders, between the cylinders and the respective side walls 01' the casing and serving to support the 10 track ring, the slots of said members having their inner ends substantially in alignment with said fluid inlet passage, and extending radially of said members to the outer peripheries thereof respectively, and thus serving to receive oil in the casing near its center and discharge it out- A wardly under centrifugal force against the inner eriphery of the casing wall.

ROGER F. HORTON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

